Synchronized exhaust nozzle actuating system

ABSTRACT

A nozzle is formed on the exhaust end of a turbojet engine having four sets of flaps. One set of main flaps is pivotally located downstream of an exhaust opening, with a second set of balance flaps pivotally connected between said main flaps and their rear end of the exhaust opening. A third set of diverging flaps are pivotally mounted to the main flaps and extend downstream thereof with the downstream end of said diverging flaps being pivotally connected at their rearward end to a fourth set of external flaps which are pivotally mounted at their forward end to the outer housing of the engine. The nozzle actuating system comprises an actuating device on each flap having a pair of output actuating arms means thereon along with an input actuating arm means. The input actuating arm means is controlled by a cylinder and piston unit so that all of the input arm means are moved together. The output actuating arm means are each connected to the adjacent edge of an adjacent flap. This arrangement extends from flap to flap around the entire circumference of the nozzle providing a variable hoop arrangement.

United States Patent 9] Madden et al.

45] May 1,1973

[ SYNCHRONIZED EXHAUST NOZZLE ACTUATING SYSTEM [75] 'lnventors: William M. Madden, Palm Springs; Richard E. Teagle, North Palm Beach, both of Fla.

[73] Assignee: United Aircraft Corporation, East Hartford, Conn.

22 Filed: nezo, 1971 21 Appl. No.: 209,664

Primary Examiner- M. Henson Wood, Jr. Assistant,Examiner+Michael Mar Attorney-Jack N. McCarthy 5 7 ABSTRACT A nozzle is formed on the exhaust end of a turbojet engine having four sets of flaps. One set of main flaps is pivotally located downstream of an exhaust opening, with a second set of balance flaps pivotally connected between said main flaps and their rear end of the exhaust opening. A third set of diverging flaps are pivotally mounted to the main flaps and extend downstream thereof with the downstream end of said diverging flaps being pivotally connected at their rearward end to a fourth set of external flaps which are pivotally mounted at their forward end to the outer housing of the engine. The nozzle actuating system comprises an actuating device on each flap having a pair of output actuating arms means thereon along with an input actuating arm means. The input actuating arm means is controlled by a cylinder and piston unit so that all of the input arm means are moved together. The output actuating arm means are each connected to the adjacent edge of an adjacent flap. This arrangement extends from flap to flap around the entire circumference of the nozzle providing a variable hoop arrangement.

8 Claims, 4 Drawing Figures SYNCHRONIZED EXHAUST NOZZLE ACTUAT-ING SYSTEM The invention disclosed herein was made in the course of or under a contract with the Department of the Air Force.

BACKGROUND OF THE INVENTION This invention relates to actuating means for variable area nozzles for turbojet engines and while any actuating means are in the prior art, none appear to provide the cooperating movement between a given flap and the adjacent flap on each side as set forth herein, several prior art patents are identified in the specification containing various nozzle actuating means.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view illustrating the application of the invention to a turbojet engine.

FIG. 2 is an enlarged schematic view taken through the nozzle and the rear portion of the engine showing the minimum area position of the flaps of the nozzle.

FIG. 3 is a schematic view taken along the line 33 of FIG. 2.

FIG. 4 is an enlarged schematic view taken along the line 4'-4 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the engine 2 shown includes the conventional compressor section 4, the burner section 6, turbine section 8, and exhaust duct and nozzle 10. In FIG. 2, the inner case 14 is shown fixed to the outer housing structure 12 by a conical shaped connecting member 16. This member is attached to the outer housing by bolts 18 and extends forwardly to a point where it is connected to the inner casing by bolts 20, forming the section of a cone. An inner liner 22 is positioned around and fixedly spaced from the inner side of inner case 14.

A plurality of main flaps 30 are mounted for pivotal movement at the rear of the outer housing structure 12. These flaps are each pivotally mounted on a bracket member 32 which extends inwardly from the end of the structure 12. Each flap 30 is pivotally mounted approximately one-third of the distance. from its forward edge and each pivotal mounting is substantially in axial alignment with the inner liner 22. Each main flap 30 has an actuating device 33 mounted thereon which is connected to each adjacent flap, so that when all of the actuating devices 33 are moved, all of the main flaps are actuated.

Each actuating device comprises a base member 100 fixed near the rear end of its respective flap 30 with a shortshaft 102 extending outwardly from the rear surface of the flap on the center line thereof. A cylindrical member 104 is mounted for rotation thereon. Each cylindrical member 104 has a pair of output actuating arm means 106 and 108 thereon along with an input actuating arm means 110. Each actuating arm means comprises two arms spaced to receive the end of a link therebetween. A nut 105 is threadably mounted on the free end of each shaft 102 and limits the axial movement of the cylindrical member 104.

Each actuating arm means 106 has its free end connected by a link 112 to a bracket 114 on the adjacent edge of an adjacent flap. Each actuating arm means 108 has its free end connected by a link 116 to a bracket 118 on the adjacent edge of the other adjacent flap (see FIG. 3). Where each arm means and bracket is attached to a link a ball joint is provided for ease of movement.

With reference to FIG. 3, the actuating device 33 of flap 30A has its link 112 connected to the bracket 114 of flap 30C while link 116 is connected to bracket 118 on flap 303. It can be seen that the link 112 coming from the actuating device on flap 30B is connected to the bracket 114 on flap 30A. In a like manner, the link 116 coming from the actuating device on flap 30C is connected to the bracket 118 on flap 30A. In a construction built, 15 main flaps were used and the construction extended from flap to flap around the entire circumference thereof providing a variable hoop arrangement.

So that all the main flaps are moved in unison, the free end of each of the arms 110 is connected to an actuator unison ring 36 by an actuating link 38. A plurality of actuating cylinder and piston units 40 are mounted in the space between the housing structure 12 and inner case 14 in front of the connecting member 16. An actuating rod 39 extends from each of the cylinder and piston units 40 and is attached to the actuator unison ring 36. The unison ring 36 is centered within and slides on track members 37. Each actuating rod 39 extends through an opening 41 in the connecting member 16. A nozzle actuator 42 connects one side of the cylinder and piston unit to an actuating pressure while opening the opposite side to drain whereby movably positioning the main flaps 30. An arrangement ofthis type is shown in U. S. Pat. No. 2,815,643.

A plurality of balance flaps 50 extend forwardly of the main flaps 30. Each flap 50 has its rearward end pivotally connected to the forward end of a main flap 30 while its forward end has cylindrical means 51 thereon which is mounted for axial movement in a track means 53. Each track means 53 is formed between a rearward extension of the inner case 14 and a rearward extending flange 15 on the connecting member 16. While a simple cylinder and track means pivotally connected to the rearward end of a main flap 30*while its rearward end is pivotally connected to the rear end of an external flap 70. Each external flap has its forward end pivotally mounted at the rear end of the housing structure 12, just rearwardly of the bracket members 32. Each of these pivotal connections includes a lost-motion movement.

Each of the annular set of flaps, the balance flaps 50, the main flaps 30, the divergent flaps 60, and the external flaps 70, can have seal means 77 positioned along adjacent side edges of cooperating flaps to prevent an excessive amount of leakage therebetween. Seal means are shown in U. S. Pat. No. 2,972,226; U. S. Pat. No. 3,004,385; U. S. Pat. No. 2,697,907; and U. S. Pat. No. 2,910,828.

In operation, it can be seen that when the nozzle actuator 42 directs an actuating pressure to the forward side of the cylinder and piston unit 40, the actuating rod 39 will place the unison ring 36 in its rearward position, as shown in FIG. 2, with the flaps positioned so as to form the minimum throat portion at the hinge location between flaps 30 and 60. When the nozzle actuator 42 directs an actuating pressure to the rearward side of the cylinder and piston unit 40, the actuating rod 39 will be moved forwardly placing the actuator unison ring 36 in a more forward position with the flaps positioned differently forming a larger opening at the rear end of the flaps 30.

Stop means can be located in the cylinder and piston unit 40 or between the bracket members 32 and 34 to predetermine the range of movement of the main flaps 30 and 30A, and therefore the remaining associated flaps, to arrive at the desired limit positions of the flaps.

A nozzle system such as shown in this application, is disclosed in co-pending application Ser. No. 209,665, filed Dec. 20, 1971, for BALANCED FLAP CON- VERGlNG/DIVERGING NOZZLE to Craig E. Swavely et al. Further, an exit area schedule selector system for a nozzle such as disclosed herein is disclosed in copending application Ser No. 209,803, filed Dec. 20, 1971, for EXIT AREA SCHEDULE SELECTOR SYSTEM by Kenneth E. Harmon. A seal means for a nozzle such as disclosed herein is set forth in co-pending application Ser. No. 210,017, filed Dec. 20, 1971, for SEAL CENTERING AND RETENTION MEANS by Connie W. McMath.

We claim:

1. In combination in a jet engine, an exhaust nozzle mounted thereon, said nozzle comprising a circumferential row of pivotally mounted main flaps, each flap having an inner and outer surface, said inner surfaces forming an inner surface of said nozzle for controlling flow therethrough, each of said main flaps having an actuating device mounted for rotation on the outer side thereof, each of said actuating devices being connected to the adjacent main flaps for moving said flaps, actuating means being connected to said actuating devices for operating said actuating devices and therefore said adjacent main flaps.

2. A combination as set forth in claim 1 wherein each actuating device includes a member mounted for rotational movement on the outer side of a flap, each member having two output arms and an input arm, one output arm being connected to one adjacent main flap while the other output arm is connected to the other adjacent main flap, said actuating means being connected to said input arm for rotating said member and therefore said adjacent main flaps.

3. A combination as set forth in claim 1 wherein each actuating device is mounted adjacent the end thereof to minimize actuating forces.

4. A combination as set forth in claim 2 wherein the output arm are each connected to the free end of a bracket extending outwardly from an adjacent flap.

5. A combination as set forth in claim 4 wherein said two output arms are substantially in a plane parallel to the outside of the flap.

6. A combination as set forth in claim 1 wherein said actuating means includes a unison ring mounted for axial movement with respect to said pivotally mounted main flaps, an actuating rod extending from said unison ring to each actuating device for rotating it.

7. A combination as set forth in claim 2 wherein connecting means connect each output arm to its cooperating adjacent main flap.

8. A combination as set forth in claim 7 wherein each connecting means is a link pivotally mounted at one end to an output arm and pivotally connected at its other end to its cooperating adjacent main flap. 

1. In combination in a jet engine, an exhaust nozzle mounted thereon, said nozzle comprising a circumferential row of pivotally mounted main flaps, each flap having an inner and outer surface, said inner surfaces forming an inner surface of said nozzle for controlling flow therethrough, each of said main flaps having an actuating device mounted for rotation on the outer side thereof, each of said actuating devices being connected to the adjacent main flaps for moving said flaps, actuating means being connected to said actuating devices for operating said actuating devices and therefore said adjacent main flaps.
 2. A combination as set forth in claim 1 wherein each actuating device includes a member mounted for rotational movement on the outer side of a flap, each member having two output arms and an input arm, one output arm being connected to one adjacent main flap while the other output arm is connected to the other adjacent main flap, said actuating means being connected to said input arm for rotating said member and therefore said adjacent main flaps.
 3. A combination as set forth in claim 1 wherein each actuating device is mounted adjacent the end thereof to minimize actuating forces.
 4. A combination as set forth in claim 2 wherein the output arm are each connected to the free end of a bracket extending outwardly from an adjacent flap.
 5. A combination as set forth in claim 4 wherein said two output arms are substantially in a plane parallel to the outside of the flap.
 6. A combination as set forth in claim 1 wherein said actuating means includes a unison ring mounted for axial movement with respect to said pivotally mounted main flaps, an actuating rod extending from said unison ring to each actuating device for rotating it.
 7. A combination as set forth in claim 2 wherein connecting means connect each output arm to its cooperating adjacent main flap.
 8. A combinaTion as set forth in claim 7 wherein each connecting means is a link pivotally mounted at one end to an output arm and pivotally connected at its other end to its cooperating adjacent main flap. 